SM_21b: Oral Cavity

Question 1

Oral cavity is contained within the ____ and contains the ____, ____, and ____

Answer 1

Oral cavity is contained within the dental arches and contains the tongue (anterior 2/3), lingual frenulum with submandibular salivary gland openings, and sublingual salivary glands under plica sublingualis

Question 2

Vestibule is between ____ and ____ and contains the ____, ____, and ____

Answer 2

Vestibule is between lips and teeth and contains the loose and attached gingiva (gums), labial frenulum, and openings of parotid gland ducts

Question 3

Greater palatine nerve is sensory to the ____, while lesser palatine nerve is sensory to the ____

Answer 3

Greater palatine nerve is sensory to the hard palate, while lesser palatine nerve is sensory to the soft palate

Question 4

Bony palate in roof of oral cavity is composed of the ____ and ____

Answer 4

Bony palate in roof of oral cavity is composed of the maxilla and horizontal plates of the palatine bones

Question 5

Soft palate has the ____ behind the bony palate and numerous ____

Answer 5

Soft palate has the uvula behind the bony palate and numerous salivary glands

Question 6

____ is floor of oral cavity

Answer 6

Mylohyoid muscle is floor of oral cavity

Question 7

Coronoid process of mandible is insertion for ____

Answer 7

Coronoid process of mandible is insertion for temporalis muscle

Question 8

____ is lateral wall of oral cavity and is innervated by ____

Answer 8

Buccinator muscle is lateral wall of oral cavity and is innervated by CN VII (facial)

Question 9

Oral cavity - pharynx boundary is delineated by the ____ and ____

Answer 9

Oral cavity - pharynx boundary is delineated by the sulcus terminalis and palatoglossal arch

(posterior third of tongue has lingual tonsils in pharynx, foramen cecum is origin of thyroid gland)

Question 10

____ raises soft palate for mouth breathing

Answer 10

Levator palati raises soft palate for mouth breathing

(both arch muscles pull soft palate down against tongue for nose breathing, posterior third of mouth is bumpy because of lingual tonsils)

Question 11

____ is between the palatoglossal and palatopharyngeal arches

Answer 11

Palatine tonsil is between the palatoglossal and palatopharyngeal arches

Question 12

Lining of oral cavity comes from ____

Answer 12

Lining of oral cavity comes from ectodermal stomodeum

• Inside lining of first pharyngeal arch
• General sensory neurons in: lingual nerve (V3), buccal nerve (V3), nasopalatine nerve (V2), and greater palatine nerve (V2)
• Lesser palatine nerve (V2) does soft palate

Question 13

____ is site of the thyroid diverticulum

Answer 13

Foramen cecum is site of the thyroid diverticulum

Question 14

Developing tongue is on the floor of the ____ and ____

Answer 14

Developing tongue is on the floor of the stomodeum and foregut

(Arch 2 diminishes: most of 2nd arch migrates over face to form muscles of facial expression)

Question 15

Describe the midsagittal section through the stomodeum and foregut

Answer 15

Midsagittal section through the stomodeum and foregut

Question 16

____ and ____ flank the stomodeum

Answer 16

Frontonasal process and maxillary / mandibular parts of first pharyngeal arch flank the stomodeum

(day 24)

(frontonasal process contributes to forehead and nose)

Question 17

Medial and lateral nasal swellings appear on the ____ at days 31 and 33

Answer 17

Medial and lateral nasal swellings appear on the frontonasal process at days 31 and 33

Question 18

Medial nasal swellings fuse into an ____, forming the ____

Answer 18

Medial nasal swellings fuse into an intermaxillary segment, forming the primary palate

(day 35)

(cartilage in front of external auditory meatus comes from Arch 1, cartilage behind comes from Arch 2)

Question 19

Intermaxillary segment gives rise to the ____ plus the ____ and ____ at days 40 to 48

Answer 19

Intermaxillary segment gives rise to the primary palate plus the external nose and part of the upper lip at days 40 to 48

Question 20

Mesoderm inside the processes needs to fuse to form ____

Answer 20

Mesoderm inside the processes needs to fuse to form clefts

• Nasolacrimal groove -> duct
• Midline cleft is when mesoderm forming Arch 2 does not migrate to orbicularis oris)

Question 21

Olfactory placodes invaginate as ____

Answer 21

Olfactory placodes invaginate as nasal sacs

(primary palate separates primitive nasal cavity from oral cavity)

Question 22

Nasal sacs break through the ____

Answer 22

Nasal sacs break through the stomodeum

(primary palate, nasal septum, and primitive nasal cavity and oral cavity that are further separated by a secondary palate)

Question 23

Secondary palate comes from the ____

Answer 23

Secondary palate comes from the lateral palatine process

• Primary palate, primary nasal septum, and lateral palatine processes grow towards each other
• Secondary palate helps you breathe while chewing

Question 24

Lateral palatine process fuses to each other and then to nasal septum to form ____, ____, and ____

Answer 24

Lateral palatine process fuses to each other and then to nasal septum to form posterior maxilla, palatine bones, and soft palate

Question 25

____ and ____ come from the primary palate

Answer 25

Premaxilla and upper incisors come from the primary palate

Question 26

____ occurs when palates do not fuse properly

Answer 26

Cleft palate occurs when palates do not fuse properly

• Failure of fusion of one lateral palatine process with nasal septum and other palatine process
• If nasal cavity not separated from oral cavity, no suction so cannot feed

Question 27

Tongue muscles receive ____ innervation from ____

Answer 27

Tongue muscles receive somatomotor innervation from CN XII (hypoglossal)

• Hypoglossal nerve innervates intrinsic tongue muscles and most extrinsic
• Palatoglossus is innervated by the vagus nerve

Question 28

Genioglossus muscle is innervated by ____ and functions to ____, ____, and ____ the tongue

Answer 28

Genioglossus muscle is innervated by CN XII (hypoglossal) and functions to protract, retract, and depress the tongue

• Only muscle that can protract the tongue and keep it out of the airway / keep pharynx open

Question 29

Hyoglossus muscle is innervated by ____ and functions to ____ and ____ the tongue

Answer 29

Hyoglossus muscle is innervated by ____ and functions to depress and retract the tongue

Question 30

Styloglossus muscle is innervated by ____ and functions to ____ and ____ the tongue

Answer 30

Styloglossus muscle is innervated by CN XII (hypoglossal) and functions to retract and elevate the tongue

Question 31

Describe sensory innervation of the tongue

Answer 31

Sensory innervation of the tongue

• General sensory: V3
• Visceral sensory: X, IX
• Taste: X, IX, VII via chorda tympani

Question 32

____ is the pretrematic nerve of the facial nerve and brings taste to the ____ and parasympathetics to the ____

Answer 32

Facial nerve is the pretrematic nerve of the facial nerve and brings taste to the anterior 2/3 of the tongue and parasympathetics to the salivary glands

Question 33

Lingual nerve spirals ___

Answer 33

Lingual nerve spirals under the duct of the submandibular gland

• Lingual nerve is much more superficial than CN XII, which enters muscle
• Lingual nerve and CN XII pass between hypoglossus and mylohyoid muscles